Zenith DV140 Service Manual page 11

ELECTRICAL TROUBLESHOOTING GUIDE
1. Power check flow.....................................................................................................................3-2
2. System operation flow ............................................................................................................3-3
3. Test & debug flow ....................................................................................................................3-4
DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING
1. SYSTEM 27MHz CLOCK, RESET, FLASH R/W SIGNAL. ....................................................3-10
2. SDRAM CLOCK ......................................................................................................................3-12
3. TRAY OPEN/CLOSE SIGNAL ................................................................................................3-12
4. SLED CONTROL RELATED SIGNAL(NO DISC CONDITION) .............................................3-13
5. LENS CONTROL RELATED SIGNAL(NO DISC CONDITION) .............................................3-13
6. LASER POWER CONTROL RELATED SIGNAL(NO DISC CONDITION) ............................3-14
7. DISC TYPE JUDGEMENT WAVEFORM ................................................................................3-14
8. FOCUS ON WAVEFORM........................................................................................................3-16
9. SPINDLE CONTROL WAVEFORM(NO DISC CONDITION ...................................................3-17
10. TRACKING CONTROL RELATED SIGNAL(System checking).........................................3-18
11. MT1389D AUDIO OPTICAL AND COAXIAL OUTPUT (SPDIF) ..........................................3-19
12. MT1389D VIDEO OUTPUT WAVEFORM .............................................................................3-19
13. AUDIO OUTPUT FROM AUDIO DAC ..................................................................................3-20
BLOCK DIAGRAMS
1. Overall Block Diagram ..........................................................................................................3-21
2. Power(SMPS) Block Diagram ...............................................................................................3-22
3. SERVO Block Diagram ..........................................................................................................3-23
4. MPEG & MEMORY Block Diagram .......................................................................................3-24
5. VIDEO & AUDIO Block Diagram ...........................................................................................3-25
CIRCUIT DIAGRAMS
1. Power(SMPS) Circuit DIAGRAM...........................................................................................3-26
2. AV/JACK Circuit DIAGRAM...................................................................................................3-28
3. SYSTEM Circuit DIAGRAM ...................................................................................................3-30
4. DRIVER Circuit DIAGRAM.....................................................................................................3-32
5. TIMER Circuit DIAGRAM .......................................................................................................3-34
• CIRCUIT VOLTAGE CHART ....................................................................................................3-36
PRINTED CIRCUIT DIAGRAMS
1. MAIN P.C.BOARD ...................................................................................................................3-38
2. KEY P.C.BOARD.....................................................................................................................3-40
3. TIMER P.C.BOARD .................................................................................................................3-41
4. SMPS P.C.BOARD ..................................................................................................................3-42
SECTION 3
ELECTRICAL
CONTENTS
..................................................................................................................3-21
................................................................................................................3-26
............................................................................................3-38
......................................................................3-2
3-1
....................3-10